The purpose of this study is to calculate an "Efficacy:Toxicity Ratio" for different inhaled corticosteroid preparations now available in the United States. Our approach to calculating this ratio is to compare the clinical effects of doses of different inhaled corticosteroids selected to cause comparable systemic effect (as estimated from plasma cortisol AUC in DICE). "Clinical Efficacy" for these doses will be assessed by measuring tests of pulmonary function, such as forced expired volume in one second (FEV1) and Forced Vital Capacity (FVC) measured before and after bronchodilator treatment, bronchial reactivity to methacholine, and the fall in FEV1 provoked by exercise at a work rate causing an increase in heart rate to 80% of the maximum predicted asthma. Clinical efficacy will also be measured by assessing clinical severity of asthma, such as symptoms, rescue use of an inhaled beta-agonist, peak flow, and nocturnal wakings as recorded in a diary. Also measured will be the percentage of eosinophils in induced sputum samples as a marker of airway mucosal inflammation.